Experimental study on gas uniformity at the inlets of six cyclones in a CFB with multi-tracer gas method--颗粒学报PARTICUOLOGY

Zhang, Q., Cheng, L., Li, K., Ma, Z., & Yu, Q. (2024). Experimental study on gas uniformity at the inlets of six cyclones in a CFB with multi-tracer gas method. Particuology, 94, 187-196. https://doi.org/10.1016/j.partic.2024.08.002

Experimental study on gas uniformity at the inlets of six cyclones in a CFB with multi-tracer gas method

Qingyu Zhang, Leming Cheng^*, Kun Li, Zhangke Ma, Qifeng Yu

Institute for Thermal Power Engineering, State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou, 310027, China

10.1016/j.partic.2024.08.002

Volume 94, November 2024, Pages 187-196

Received 30 April 2024, Revised 3 July 2024, Accepted 4 August 2024, Available online 10 August 2024, Version of Record 24 August 2024.

E-mail: lemingc@zju.edu.cn

Highlights

• A multi-tracer gas method is used to investigate uniformity of different gases at multi-cyclone inlets.

• The uniformity of multi-gas distribution varies with their properties.

• The extent of the impact of operational parameters on multi-gas uniformity correlates with gas density.

Abstract

To investigate the non-uniform distribution of different gases passing through the parallel cyclones, experiments were conducted on a circulating fluidized bed (CFB) equipped with six asymmetrical cyclones. A multi-tracer gas method was used, with CO, O₂, and CO₂ chosen to represent gases with different properties in the flue gas at the inlets of the cyclones. The uniformity of multi-gas distribution was evaluated by measuring the concentration deviations of each tracer gas passing through individual cyclones. The results indicate that the concentrations of multi-tracer gases are higher in the middle cyclone among the three, which are located on the tracer gas injection side during the test of single-side secondary air (SA) tracing. The maximum concentration deviation of tracer gases is for CO₂, while the minimum is for CO. At the three cyclone inlets on the opposite side, the tracer gas with higher density exhibits a more uniform distribution, and the gas uniformity decreases as the density decreases. The effects of superficial velocity, SA ratio, bed inventory, and tracer gas injection region on the uniformity of gas distribution were studied. The results show that superficial velocity and SA ratio primarily affect the uniformity of higher density gases, while bed inventory has a greater influence on lower density gases. The gas distributions are most non-uniform, especially for CO₂, when the tracer gas injection region is near the rear wall closer to the induced draft fan during the test of regional SA tracing.

Graphical abstract

Keywords

Circulating fluidized bed; Multi-gas uniformity; Parallel cyclones; Multi-tracer gas method

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